In a road charging system, a scheme of recognizing that a vehicle passes through a charging point to perform charging through communication between a wireless communication device installed at each charging point and a wireless communication device provided in the vehicle passing through the point, or by reading, for example, a number plate of the vehicle with a camera installed on a roadside is widely used. Further, there is a position measurement method for a vehicle using a global navigation satellite system (GNSS), comparing information of the position with map information including information of a charging point to determine passage of the charging point and perform charging.
Further, in a next generation road charging system, a mechanism for estimating a position of a vehicle using a combination of position measurement using a GNSS and an autonomous position measurement method using an acceleration sensor or the like included in a vehicle and performing charging on the basis of, for example, a travel route of the vehicle or a stay time in a specific area has been examined. To realize this next-generation road charging system, it is necessary to recognize accurate position information of the vehicle. For example, Patent Literature 1 describes a method of receiving a signal from a quasi-zenith satellite using a receiver mounted on an on-board unit and measuring an accurate position of the vehicle.